如何在kivy的单个屏幕上独立旋转两个矩形小部件？

Question

我正在学习 Python 编程并开发一个简单的游戏应用程序，在该应用程序中，我需要在单个屏幕上单击它们时旋转两个矩形，但发生的情况是当我单击其中一个矩形时，两个矩形都沿原点旋转正在单击的那个矩形，但另一个矩形不是这种情况，实际上它的位置也不是应该的，并且当单击分配的位置（该矩形不存在的位置）时，它会在不旋转的情况下旋转两个矩形。我只需要在独立点击时旋转两个矩形。 很难解释，所以请尝试执行代码并找出发生了什么。

from kivy.app import App
from kivy.graphics import Rotate, Rectangle, Ellipse, Color
from kivy.lang import Builder
from kivy.uix.screenmanager import ScreenManager, Screen, CardTransition
from kivy.uix.widget import Widget
from kivy.properties import ObjectProperty, NumericProperty, ReferenceListProperty, ListProperty
from kivy.uix.floatlayout import FloatLayout

Builder.load_string('''

<Stage_2>:
    object2: Object2
    object3: Object3

    Object2:
        id: Object2
        center: self.rotate_origin

    Object3:
        id: Object3
        center: self.rotate_origin

<Manager>:
    id: screen_manager

    Screen:
        name:"P"
        FloatLayout:

            Button:
                pos_hint:{"x":0.2,"y":0.05}
                size_hint: 0.6, 0.2
                font_size: (root.width**2 + root.height**2) / 13**4
                text: "Play"
                background_color: 255,0,1,1
                on_release:
                    root.transition.direction = "up"        
                    root.current = "stage2"

    Screen:
        name: 'stage2'
        Stage_2:
            id:s2

''')

class Object2(Widget):
    def __init__(self, *args, **kwargs):
        Widget.__init__(self, *args, **kwargs)
        self.rect_pos_x = 500
        self.rect_pos_y = 425
        self.rect_pos = self.rect_pos_x, self.rect_pos_y
        self.rect_width = 150
        self.rect_height = 30
        self.rect_size = self.rect_width, self.rect_height
        self.rotate_origin_x = self.rect_pos_x + self.rect_width / 2
        self.rotate_origin_y = self.rect_pos_y + self.rect_height / 2
        self.rotate_origin = self.rotate_origin_x, self.rotate_origin_y
        self.angle = 135
        print('rect 1')
        with self.canvas:
            Rotate(origin=self.rotate_origin, angle=self.angle)
            Color(rgb=(0,197,68))
            Rectangle(pos=self.rect_pos, size=self.rect_size)

    def rotate(self):
        self.canvas.clear()
        self.angle += 90
        if (self.angle > 315):
            self.angle = 225
        with self.canvas:
            Rotate(origin=self.rotate_origin, angle=self.angle)
            Color(rgb=(0, 255, 100))
            Rectangle(pos=self.rect_pos, size=self.rect_size)

    def on_touch_up(self, touch):
        if self.collide_point(*touch.pos):
            self.rotate()
            print(self.angle)
class Object3(Widget):
    def __init__(self, *args, **kwargs):
        Widget.__init__(self, *args, **kwargs)
        self.rect_pos_x = 500
        self.rect_pos_y = 250
        self.rect_pos = self.rect_pos_x, self.rect_pos_y
        self.rect_width = 150
        self.rect_height = 30
        self.rect_size = self.rect_width, self.rect_height
        self.rotate_origin_x = self.rect_pos_x + self.rect_width / 2
        self.rotate_origin_y = self.rect_pos_y + self.rect_height / 2
        self.rotate_origin = self.rotate_origin_x, self.rotate_origin_y
        self.angle = 135
        print('rect 2')
        with self.canvas:
            Rotate(origin=self.rotate_origin, angle=self.angle)
            Color(rgb=(1,255,0))
            Rectangle(pos=self.rect_pos, size=self.rect_size)

    def rotate(self):
        self.canvas.clear()
        self.angle += 90
        if (self.angle > 315):
            self.angle = 225
        with self.canvas:
            Rotate(origin=self.rotate_origin, angle=self.angle)
            Color(rgb=(0, 255, 100))
            Rectangle(pos=self.rect_pos, size=self.rect_size)

    def on_touch_up(self, touch):
        if self.collide_point(*touch.pos):
            self.rotate()
            print(self.angle)

class Stage_2(Widget):
    object2 = ObjectProperty(None)
    object3 = ObjectProperty(None)

class Manager(ScreenManager):
    pass

sm = Manager()

class ScreensApp(App):
    def build(self):
        return sm

if __name__ == '__main__':
    ScreensApp().run()

Answer 1

如果您在canvas 指令中包含PushMatrix() 和PopMatrix()，则只有当前的Widget 会受到影响。然后，如果你将Widgetsize 和pos 调整为Rectangle，你应该会变得更好（但不是完美）collide_point 性能：

    with self.canvas:
        PushMatrix()
        Rotate(origin=self.rotate_origin, angle=self.angle)
        Color(rgb=(1,255,0))
        Rectangle(pos=self.rect_pos, size=self.rect_size)
        PopMatrix()
        self.pos = self.rect_pos
        self.size = self.rect_size

每当您使用涉及Rotation、Scale 或Translate 的with self.canvas 时，都需要执行此操作。 collide_point() 仍将查看 Widget size 和 pos，而不是 Rectangle，但至少 Widget 和它的 Rectangle 的中心应该重合。